Search Publications
Post-AGB candidate IRAS 02143+5852: Cepheid-like variability, three-layer circumstellar dust envelope and spectral features
Rudy, R. J.; Shugarov, S. Yu; Ikonnikova, N. P. +8 more
We present the results of multicolour UBVRCICJHK photometry, spectroscopic analysis and spectral energy distribution (SED) modelling for the post-AGB candidate IRAS 02143+5852. We detected Cepheid-like light variations with the full peak-to-peak amplitude ΔV ~ 0.9 mag and the pulsation period of about 24.9 d. The phased light…
Time-variable diffuse γ-ray foreground
Siegert, Thomas
While the data analysis of γ-ray telescopes has now become more robust, some signals may be misinterpretations of a time-variable foreground emission from the Solar system, induced by low-energy cosmic-ray interactions with asteroids. Our goal is to provide emission templates for this time-variable diffuse γ-ray foreground by considering the popul…
Cold quasar investigation: comparing star formation rates to black hole growth
Kirkpatrick, Allison; Coleman, Brandon; Mintz, Sasha
Cold quasars are a rare population of luminous, unobscured quasars associated with host galaxies that have a high star formation rate. We aimed to study the host galaxies of 64 of these cold quasars in order to probe how the supermassive black holes and host galaxies were co-evolving. We compiled data from the XMM-XXL survey and cross-matched with…
GMF G214.5-1.8 as traced by CO: I - cloud-scale CO freeze-out as a result of a low cosmic-ray ionization rate
Higgins, R.; Sánchez-Monge, Á.; Suri, S. +6 more
We present an analysis of the outer Galaxy giant molecular filament (GMF) G214.5-1.8 (G214.5) using IRAM 30m data of 12CO, 13CO, and C18O. We find that the 12CO (1-0) and (2-1) derived excitation temperatures are near identical and are very low, with a median of 8.2 K, showing that the gas is extremely c…
Chemical compositions of semiregular variable red giants
Lambert, David L.; Pozhath, Ramya
A sample of warm, low-level semiregular variables chosen from the General Catalogue of Variable Stars is studied for their chemical compositions by analysing high-resolution optical spectra. The abundance ratios from Na/Fe to Eu/Fe displayed by these and previously analysed semiregular variables are quite similar to ratios displayed by normal red …
Searching for triple systems unbound by supernovae
Kochanek, Christopher S.; Barboza, Karina
A large fraction of massive stars are found in higher order systems where the presence of a tertiary may significantly modify the system's evolution. In particular, it can lead to increased numbers of compact object binaries and accelerate their mergers with important implications for gravitational wave observations. Using Gaia, we constrain the n…
The Keck-HGCA Pilot Survey - II. Direct imaging discovery of HD 63754 B, a 20 au massive companion near the hydrogen burning limit
Jensen-Clem, Rebecca; Salama, Maïssa; Currie, Thayne +15 more
We present the joint astrometric and direct imaging discovery, mass measurement, and orbital analysis of HD 63754 B (HIP 38216 B), a companion near the stellar-substellar boundary orbiting
An alternative interpretation of magnetars' traits deduced from the observational data on their outburst fluxes and spectra
Ardavan, Houshang
By applying the Efron-Petrosian method to the fluxes S and distances D of the magnetars listed in the Magnetar Outburst Online Catalogue, we show that the observational data are consistent with the dependence
Thermal X-ray emission in the western half of the LMC superbubble 30 Dor C
Zhou, Ping; Chen, Yang; Sun, Wei +4 more
While 30 Dor C is a unique superbubble in the Large Magellanic Cloud for its luminous non-thermal X-ray emission, the thermal X-ray emission it emanates has not yet been thoroughly investigated and well constrained. Based on the separate ~1 Ms deep XMM-Newton and Chandra observations, we report the discovery of the thermally emitting plasma in som…
Discovery of double stars by Giovanni Battista Hodierna in 1654
Caballero, J. A.; González-Payo, J.
It has been generally accepted that the originators of the double star astronomy were Christian Mayer and William Herschel. We recovered the memory of the poorly known Italian astronomer Giovanni Battista Hodierna, who published the first catalogue of stellar binaries over a century before Mayer and Herschel. We analysed the fourth section of 1654…